docs: def new_issuer(self, issuer_idx, info=None):
          """
          Add a new issuer to the dataset with the given data.
  
          Parameters:
              issuer_idx (str): The id to associate the issuer with. If None or already exists, one is
                                generated.
              info (dict, list): Additional info of the issuer.
  
          Returns:
              Issuer: The newly added issuer.
          """
  
          new_issuer_idx = issuer_idx
  
          # Add index to idx if already existing
          if new_issuer_idx in self._issuers.keys():
              new_issuer_idx = naming.index_name_if_in_list(new_issuer_idx, self._issuers.keys())
  
          new_issuer = issuers.Issuer(new_issuer_idx, info=info)
          self._issuers[new_issuer_idx] = new_issuer
  
          return new_issuer